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hideakitai / ESP32DMASPI

SPI library for ESP32 which use DMA buffer to send/receive transactions
MIT License
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SPI slave sends data using SPI_MODE3. Master receives data incorrectly. #2

Closed hu-Eric closed 3 years ago

hu-Eric commented 3 years ago

SPI slave is initialized to SPI_MODE2, and master receives the data correctly

hideakitai commented 3 years ago

@hu-Eric Which code are you talking about?

hu-Eric commented 3 years ago

// make sure to use DMA buffer if ((dma_chan != 1) && (dma_chan != 2)) { printf("[WARNING] invalid DMA channel %d, force to set channel 2. make sure to select 1 or 2\n", dma_chan); dma_chan = 2; } if ((mode != SPI_MODE1) && (mode != SPI_MODE3)) { printf("[WARNING] invalid SPI channel %d, force to set SPI_MODE3. make sure to select MODE1 or MODE3 (because of DMA)\n", mode); mode = SPI_MODE3; } Why set it to SPI_MODE3? The receiving data sent to the master device is different from the data sent. Setting it to SPI_MODE2 can get the correct data.

hideakitai commented 3 years ago

Please see https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/peripherals/spi_slave.html#restrictions-and-known-issues

If you still have the problem, please let me know ide version, esp32 version, library version, minimum code which can reproduce it, and schematic(connection).